The gauge field configurations that have been used to evaluate the above observables, had been generated previously in calculations of the QCD equation of state [1]}, [2]} and the transition temperature [3]}, [4]}. An improved staggered fermion action (p4-action) [5]} that strongly reduces lattice cut-off effects in bulk thermodynamics at high temperature has been used. The strange quark mass has been tuned close to its physical value and the light quark masses have been chosen to be one tenth of the strange quark mass. This corresponds to a line of constant physics on which the kaon mass is close to its physical value and the lightest pseudo-scalar mass is about 220 MeV.
